Not only high-hardness, but also nonmagnetic property and high corrosion resistance are required for parts that need wear resistance and are applied to, electronic industries such as machine parts, precision parts and molds, which are used in magnetic atmosphere.
The JIS SUH660 steel, titanium alloys or copper alloys, etc. are applied for the machine parts, but their hardness or corrosion resistance are not sufficient, and so far there have been no material that satisfies nonmagnetic, high corrosion resistance and high hardness.
There has been proposed nickel-based high-hardness alloys containing 0.1% (by weight) or less of carbon (C), 2.0% (by weight) or less of silicon (Si), 2.0% (by weight) or less of manganese (Mn), 30 to 45% (by weight) of chromium (Cr), 1.5 to 5.0% (by weight) of aluminum (Al), and the balance being unavoidable impurities and nickel (Ni), the alloy being strengthened by the composite precipitation of γ′ (gamma prime: Ni3Al) phase and ΕCr (alpha-chromium) phase, as described in Reference 1.    [Reference 1] JP2002-69557A
The existent nickel-based high-hardness alloys of the Reference 1 are non-magnetic and have an enhanced corrosion resistance owing to the addition of chromium but its hardness is at most 600 to 720 HV and therefore the wear resistance is not sufficient yet. Furthermore, it has required at least 16 hours of ageing treatment to get suitable high hardness and over at least 24 hours of ageing treatment to get the maximum hardness.